Tandem surface microfluidic lithography and activation to generate patch pattern biospecific ligand and cell arrays

Area of Science:

• Surface chemistry
• Microfluidics
• Biotechnology

Background:

• Self-assembled monolayers (SAMs) on gold are crucial for surface functionalization.
• Developing methods for selective chemical modification of SAMs is essential for creating biospecific platforms.
• Existing techniques may lack flexibility or cost-effectiveness for complex patterning.

Purpose of the Study:

• To develop a rapid, inexpensive, and flexible methodology for patterning and chemically altering SAMs on gold.
• To enable chemoselective ligand immobilization for creating biospecific cell adhesion arrays.
• To demonstrate the capability for both cell patterning and ligand microarray patterning.

Main Methods:

• Combining microfluidic lithography and oxidative activation (using pyridinium chlorochromate - PCC).
• Converting hydroxyl-terminated SAMs to aldehydes for subsequent functionalization.
• Characterizing SAM formation, activation, ligand immobilization, and cell patterning using contact angle, cyclic voltammetry (CV), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and fluorescence microscopy.

Main Results:

• Demonstrated the conversion of hydroxyl-terminated SAMs to aldehydes using PCC.
• Successfully immobilized various oxyamine-containing molecules.
• Created biospecific ligand platforms for peptide-mediated cell adhesion arrays.
• Achieved both cell patterning and ligand microarray patterning.

Conclusions:

• The developed methodology is rapid, inexpensive, and flexible.
• This approach is compatible with cell culture.
• The technique provides a versatile platform for creating patterned biosurfaces for cell adhesion studies.